Phase change memory devices use phase change materials, i.e., materials that can be electrically switched between a generally amorphous and a generally crystalline state, for electronic memory application. One type of memory element utilizes a phase change material that can be, in one application, electrically switched between a structural state of generally amorphous and generally crystalline local order or between different detectable states of local order across the entire spectrum between completely amorphous and completely crystalline states.
Typical materials suitable for such application include those utilizing various chalcogenide elements. These electrical memory devices typically do not use field effect transistor devices, but comprise, in the electrical context, a monolithic body of thin film chalcogenide material. The state change materials are also truly non-volatile in that, when set in either a crystalline, semi-crystalline, amorphous, or semi-amorphous state representing a resistance value, that value is retained until reset as that value represents a physical state of the material (e.g., crystalline or amorphous).
A phase-change memory device may comprise an opening in a dielectric material that is filled with a phase-change material such as a chalcogenide material. However, typical dielectric materials and chalcogenide materials do not chemically bond well together. As a result, the layer of phase-change material may peel during subsequent manufacturing of the phase-change device, which in turn, may affect the yield or reliability of the device.
Thus, there is a continuing need for better ways to manufacture phase-change memory devices.
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For examples the dimensions of some of the elements are exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.